Funguria-Introduction, Common fungi, Clinical Feature, Lab Diag

Introduction

Table of Contents

Funguria refers to the presence of fungi in the urine, either due to colonization, contamination, or true urinary tract infection (UTI).

Fig. Urine sample for fungal culture and KOH mount

It is increasingly reported in hospitalized or catheterized patients, particularly those with immunosuppression, antibiotic overuse, or diabetes. Most cases are asymptomatic, but it can lead to pyelonephritis, fungal balls, or sepsis, especially in neonates and ICU patients.

Common Fungi Causing Funguria

Fungal Pathogen	Notes
Candida albicans	Most common; forms pseudohyphae
Candida glabrata	Second most common; less susceptible to azoles
Candida tropicalis	Associated with hematologic malignancy
Candida krusei	Intrinsically resistant to fluconazole
Candida parapsilosis	Catheter-associated funguria
Cryptococcus neoformans	Rare; may be seen in AIDS or renal transplant
Aspergillus spp.	Very rare; usually from contamination or systemic spread

Clinical Features

Most patients are asymptomatic.
When symptomatic:
- Dysuria, frequency, urgency
- Flank pain, fever, chills
- Cloudy or foul-smelling urine
- Fungal balls may obstruct the urinary tract in neonates or catheterized patients
- In cryptococcal funguria, symptoms may be minimal or absent

Laboratory Diagnosis

Test	Purpose
Direct Microscopy (Wet mount/KOH)	Detect yeast cells, pseudohyphae
Urine Gram stain	May reveal budding yeast
Urine Culture (SDA, CHROMagar Candida)	Confirm fungal growth; >10⁴–10⁵ CFU/mL significant
Repeat Culture	Helps differentiate colonization vs infection
Blood culture	Rule out disseminated candidiasis in high-risk cases
Urinalysis	Pyuria may be present; may also be sterile
Ultrasound/CT Scan	Detect fungal balls or obstruction in complicated cases

Fungal elements in KOH mount of urine sample — Fig. Fungal elements in the KOH mount of the urine sample

Fig. Fungal growth on Sabouraud dextrose agar after 5 days of incubation at 37 °C

Aspergillus typical structure in LPCB preparation of fungal growth on SDA — Fig. Aspergillus typical structure in the LPCB preparation of fungal growth on SDA

Fig. Conidia of Aspergillus in LPCB preparation

Fig. Urine sample of a patient for fungal culture and KOH mount assay

Fig. Heavy load of fungal elements in the KOH mount of the urine specimen

Fig. Colony morphology of Candida albicans on Sabouraud dextrose agar (SDA) tube

Fig. Germ tube test (GTT) of Candida albicans-Positive

Treatment

Indication	Treatment
Asymptomatic, low-risk patient	No treatment; remove catheter if possible
Symptomatic infection	Fluconazole is first-line if susceptible
Fluconazole-resistant strains	Use Amphotericin B deoxycholate bladder irrigation or systemic Echinocandins
Obstructing fungal balls	Surgical removal + antifungals
Cryptococcal funguria	Treat as disseminated cryptococcosis: Amphotericin B ± Flucytosine

Prevention

Avoid unnecessary urinary catheters
Minimize broad-spectrum antibiotic use
Control diabetes mellitus
Maintain good perineal hygiene
Perform regular catheter care
Screen high-risk ICU or post-op patients if symptomatic
Use prophylactic antifungals in high-risk transplant or neutropenic patients selectively

Keynotes

Funguria is mostly due to Candida spp., especially in catheterized and ICU patients.
Asymptomatic cases often don’t require treatment unless risk factors exist.
Diagnosis depends on culture, microscopy, and clinical correlation.
Fluconazole remains the treatment of choice if the isolate is susceptible.
Prevention relies on infection control, catheter care, and antibiotic stewardship.

Funguria-Introduction, Common fungi, Clinical Feature, Lab Diagnosis, Treatment, and Prevention